Liquid Crystals in Flow: A New Era in Sensing and Diagnostics

Introduction

Liquid crystals (LCs) are the delicate phases of matter that exhibit molecular order, fluidic nature, and birefringent optical properties. LCs have been developed as materials suitable for energy- and label-free reporting of the chemical changes occurring at their interfaces, such as the presence of biomolecular, gaseous, or nano-/microscopic species, or the occurrence of the chemical or biochemical interactions/reactions involving these species.

Current Limitations

LC-water interfaces were employed in the most promising sensors as a medium to facilitate the interaction of the LCs with the species. Although promising, the studies reported were limited to stagnant LC systems, which restricts their use in continuous sensing and diagnostic applications.

Project Goals

This project is designed to open a new era in the sensing and diagnostic systems involving the use of LCs by introducing a microfluidic flow. The system of interest differs significantly from their counterparts with the introduction of LC-water interfaces that facilitate the exchange of analytical species during flow. However, the design of such a system is challenging, and critical understanding is required to proceed towards the next generation LCFlow platforms.

Research Objectives

We aim to design highly sensitive, dynamically tunable, and label-free LC-based fluidic sensing platforms. Therefore, this proposal is structured to understand:

1. The effect of the presence of the "soft" interfaces and the LC interfacial anchoring on the flow regimes and the LC director profiles.
2. The role of the type, scale, shape, and the symmetry of the chemical heterogeneity at the contacting surfaces on the LC flow and configurations.
3. The dynamic influences of the changes occurring at the contact interfaces on the configuration and the optical appearance of the LC medium.

Interdisciplinary Nature

The proposal is positioned at the intersection of fundamental knowledge generation and application. It is highly interdisciplinary in nature, involving physics, chemistry, materials science, and engineering.